None.
Not applicable.
The present invention relates generally to the need to identify (track) individual pieces (e.g., ferrous metals such as steel) during dip galvanizing and more particularly to a method therefor.
In the manufacture of a stadium steel beam (by way of illustration and not limitation), the beam is fabricated according to a mechanical drawing having a drawing number and then shipped to a galvanizer. Often, the steel beam is devoid of any identification marks, other than possibly a dot peen marking or coded xe2x80x9cpunchxe2x80x9d marks. The relatively thick galvanizing coating that the galvanizer is going to apply easily later obscures such physical marks.
Traditional adhesive backed paper or polyester labels cannot be used for identification, because they would prevent a portion of the beam from being properly cleaned and the subsequent protective galvanizing would not be tight on those areas. Likely, the paper or polyester label would be destroyed by the dip galvanizing process too.
Wired on polyester or paper labels will be lost in the galvanizing dip (xcx9c850xc2x0 F.). Wired on metal tags could be used if they are deeply embossed, but such embossing does not provide for automatic identification, such as, for example, standard (black/white) bar codes. The galvanizing cleaning processes (e.g., alkali dip followed by acid dip, and flux dip, and molten zinc) will destroy a high percentage of traditional prior art painted tags.
It is the ability to provide product identification (tracking) for dip-galvanized parts to which the present invention is addressed.
A method for identifying dip-galvanized parts commences with marking a tag (e.g., metal) with identification indica for a galvanizable part. The indicia tag coating and the tag material are resistant to molten zinc. A temporary film is applied over the identification indicia. The temporary film (coating) is resistant to pre-galvanizing treatment, but is disintegrated or burned off during dipping in molten zinc (galvanizing) without obscuring the readability of the identification indicia. Finally, the metal tag is associated with the galvanizable part.
Advantages of the present invention include the ability to mark galvanized parts with readable identification indicia before and after galvanizing operations. Another advantage is that readable indicia can be computer read. A further advantage is that the galvanizing operations do not need to be altered to accommodate the invention. These and other advantages will be readily apparent to those skilled in the art based on the disclosure set forth herein.